Dani Shapiro’s new memoir, Inheritance: A Memoir of Genealogy, Paternity, and Love, was inspired by her discovery after taking a DNA test that she is not biologically related to her father. (Photo by Michael Maren)

Of all the millions of people who have spit into a plastic vial and sent their DNA off to have it analyzed, writer Dani Shapiro might be the most prepared for what happened next.

The core of Shapiro’s work — this bestselling author has written 10 books — has always concerned family issues, those tangled emotional webs we weave around each other and the secrets we keep.

“It has been a huge part of what formed me as a writer — I had an obsession with searching and digging, trying to understand,” Shapiro says, noting that half of her books are memoirs about deep, personal exploration. “I idly wondered why (I kept writing memoirs) but those were the books that continued to present themselves to me as necessary. And that comes very much out of not knowing something and writing in order to try to know.”

Part of what she didn’t know was why, with her fair hair and blue eyes, she barely resembled her parents, both Orthodox Jews from Eastern Europe — an otherness remarked upon by people throughout her life.

All is revealed when the results of an Ancestry.com test that she took “on a whim” come back: She is not her beloved father’s biological daughter after all, but the product of artificial insemination her parents turned to when they could not conceive. Why that happened and what meaning Shapiro makes of it is the subject of her riveting new memoir, “Inheritance: A Memoir of Genealogy, Paternity, and Love.”

“This discovery poured gasoline over everything I thought I knew and threw a match on it,” she says. “Now I see the whole picture.”

Dani Shapiro’s new book, “Inheritance: A Memoir of Genealogy, Paternity, and Love,” chronicles her discovery that she is not biologically related to her late father. (Courtesy of Alfred A. Knopf)

Since its release in January, the book has quickly risen to the New York Times bestseller list for nonfiction and has already been optioned by Hollywood, a clear indication that both her writing and the topic of family secrets is speaking to the hearts of millions.

“I certainly wanted it to resonate with people who had been through similar experiences or discovered there were family secrets —everybody seems to have them,” said Shapiro in a phone interview while she was on the road for her national book tour that lands in Southern California for several appearances this week.

“Adoptees, people who discover they were donor conceived, or have half siblings — there are so many of those kinds of secrets tumbling out of the closet right now,” she observes.

More like an avalanche.

She notes that in 2018 alone 7 million Ancestry.com kits were purchased — and that doesn’t take into account what might be sold for other commercial DNA services like 23andMe. (DNA kits were the No. 1 holiday gift last year, too.) Shapiro discovered while researching “Inheritance” that out of the 7 million kits, 14 percent revealed what’s known in that industry as ”NPE,” Not Parent Expected: “That’s a huge number of people. Many of them, like me, were just recreational DNA testing.”

The ease and accessibility of these DNA tests herald a historical shift, she believes. “I think this is a moment in our culture when secrets and the impossibility of secrets is reaching a deafening roar,” Shapiro observes. “Paternity, ethnicity — these were secrets people could keep since the beginning of time, and did. And now that is over. I think in a few decades the idea that there ever were these secrets is going to seem like the most ridiculous thing you’d ever heard.”

Yet the exploration she undertakes in this book is even more universal: At the center is the question: How do heredity and history combine to make us who we are?

Says Shapiro: “I was also very aware that I did not only want people that could directly relate to the material to be readers of this book, because I felt I had learned so much in this really sort of harsh and complicated, and ultimately liberating, journey. I learned so much about identity, and family, and what makes a father a father, and about nature and nurture.”

Anyone who knows Shapiro’s work understands that she was close to her father, who died in an accident when she was 23, and distant from her abusive mother. These are themes that have run throughout her work. Reconciling her experience with her biological makeup was the “emotionally challenging” part of her journey to write this book.

“One of the things I had to contend with was the deep suspicion that I was part of my father’s sadness. The man that I tried so hard to make happy. But I don’t think that diminished in any way the love he had for me,” she says. “The irony is my biological parent is the one I felt a deep disconnection from, while my father, who was not my biological parent, was the one to whom I was connected. I think that my mother looked at me for all of our shared life together and found it very challenging because I was her secret. I was a reminder of their infertility; I was not my father’s child and on some very deep animal level, she knew it.”

There’s a moment in “Inheritance” where a friend tells her, “Everyone feels other,” and that she had been the explorer to come back to teach us all something about what that means. “I very much took that to heart,” she says.

Dani Shapiro

What: The author discusses her new memoir, “Inheritance: A Memoir of Genealogy, Paternity, and Love.”

Samantha Dunn is the executive editor of Coast Magazine, and the author of several books including the novel Failing Paris and a bestselling memoir, Not By Accident: Reconstructing a Careless Life. Sam’s work is anthologized in a number of places, including the short story anthology, Women on the Edge: Writing from Los Angeles, which she co-edited. She is a member of the Writers Guild of America and teaches at Chapman University, in the UCLA Extension Writers Program and at the Idyllwild Arts Center in California.